Question: What do the following two equations represent? $-4x-5y = 1$ $15x-12y = -1$
Putting the first equation in $y = mx + b$ form gives: $-4x-5y = 1$ $-5y = 4x+1$ $y = -\dfrac{4}{5}x - \dfrac{1}{5}$ Putting the second equation in $y = mx + b$ form gives: $15x-12y = -1$ $-12y = -15x-1$ $y = \dfrac{5}{4}x + \dfrac{1}{12}$ The slopes are negative inverses of each other, so the lines are perpendicular.